Manufacture of 1-hydroxy- or 1-alkoxy anthraquinone-3-carboxylic acids



Patented July 12, 1932 SEBASTIAN GASSNEB,

or L'EvEaKUsEmon-rHE-nnmn AND,

BERT-HOLD .BIE'N'EB-T, F

eonoennoN-ree-anma GERMANY, assren ias 110 GENERAL alumina, wanna INCL,OF NEW YORK, N. Y

A coaronn'rron on nnnawann I: a

menswear: or i-iiynnoxv on i-arxoxir, aiirnnnauinonn-acannoxvnrc orns1%, Drawing. Application filed. February 7,, 1330, serial 1N0. 426,763,and in Germany February 14,1929.

The present invention. relates to a process for preparing l-hydroxy orl-alkoxy anthraquinone3-carboxylic acids and to newproducts obtainablethereby. s i

In accordance with the invention lkoxy benzophenone dicarhoxylic acids,more particularly such ones as correspond to the probable generalformula O-alkyl wherein a; and 2 mean hydrogen or halogen,

at least one 3 beinghydrogen, emeans hydrogen or halogen, aretransformed into anthraquinone derivatives by reacting upon, the formerwith strong sulfuric acid or fuming sulfuric acid with or without theaddition of boric acid. This fact was most surprising since benzophenonedicarboxylic acids containing the carboxylic acid group of nucleus 11(see the above tion of the same nucleus do not yield anthraquinonederivatives by the same treatment. Also other substituents than markedin the formula'will hinder ring formation in many cases. The conditionsof Working according to our invention may vary in the widest limits, andthis holds true as well for the ring closing agent as for the time andtemperatures to be applied. For example, the compound of theformula 0 00II l coon oooH yields l-hydroxy-anthraquinone-3-carboxylic acid in agood yield. bytreatment with concentrated sulfuric acid and boric acidat a temperature between about 140 200 U. or also by treatment withfuming sulfuric acid formula) in another posiof about 2030% content'andboricacid at about 100- 140 G. Furthermore, the compound of the formulav 0001i l ooon yields l-hydroxyA-c loroa-Ilt raquinoneiacarboxylic acid,by tre me t ith boric acid 7 and ming u furic acid of. about. 3Q= Q% SOcontent on the water bath, while working with concentrated sulfuric acidand boric acid at about 145155 G. leads to theformation ofquinizariner3-carboxylic acid in this case. Also it will be possible toavoid the simultaneous saponification of the allgox yields1:methoxy-t-hydroxyanthraquinone- 3-carboxylic acid by heating it withfuming sulfurie'acidof20% S0 content to about 80-90? C. fores'omeminutes, while when treatingthe same compound at the same temperaturewith trong sulfuric acid and boric v acid for some hours,qumizarine-El-carboxylic acid is obtained. Applicants therefore cannotgive exact limits in view of the conditions at which reaction performsbest, but it may be mentioned that the use, asring closing agent, ofconcentrated sulfuric acid or fuming sulfuricacid of a SOS content up toabout and'the application of tern-- peratures between room temperatureand about 200 C. generally will yieldanthraquinone derivatives,containinga hydroxy or alko xy groupin the l-positionand a carboxylicacid group in the 3-position in a good yield, the other substituentscontained in the nucleus being dependent not only from the startingmaterial but also from themore specific method of working.

The products thus obtainable which probably correspond to the generalformula I CODE 71 O .z

7.5.; wherein w means hydrogen or alkyl, 2 hydrogen or halogen, ,02- andy hydrogen or halo-' benzophenone-2,t dicarboxylic troduced intoasolution of 24 parts by weight gen,-at least oneg being hydrogen, formyellowto red Compounds, soluble'in strong sul-' furic acid with a yellowto bluish-red colora-v 1.. tion, in alkalies with a red to bluecoloration.

The'startin'gmaterials, that is to say'the alkoxybenzophenone'dicarboxylic acids, may be prepared, for example, bycondensing phthalic acid anhydride or a halogen substitution productthereof with a 1-hydroxy-3- E'mampZeI OCH: o ll 002B Oio coin Into asolution of 24 parts by weight of crystallized boric aciddissolved in150 parts by Weight of concentrated sulfuric acid, parts com I 1 byweight of 2 methoxy-benzophenone-2,4-

dicarboxylic acid are introduced and the mixture is heated for 2 3 hoursto a temperature of 150 Afterthat time the melt is poured into water andthe precipitated carboxylic acid -is filtered after boiling up themixture. V The 1-hydroxy-anthraquinone3- o carboxylic acid thus obtainedcrystallizes from glacial acetic acid in form of long yel- ,low needles,melting at 282-284 C. A I

Example o OOH:

. I 1 i 1 10 parts by Weight of 2 -methoxy-5 .'-chloroacid are in- 10parts by weight of 2-methoxy-5-hydroxyof crystallized boricaciddissolved in 100 parts by weight of fuming sulfuric acid of strength andthe mixture is heated for 3-4 hours to about C. The 1-hydroxy-4-chloroanthraquinone-3carboxylic acid thus produced is precipitated bypouring into water. It crystallizes in yellow-brown needles, melting at198199 C. V a Example 3 con,

coin c0211 3 Cl 3 O .10 parts by Weight of2-methoxy-5'-chlorobenzophenone-QAU-dicarboxylic acid are introducedinto a solution of 24: parts by weight of crystallized boric aciddissolved in 150 parts by weight of concentrated sulfuric acid a orfuming sulfuric acid (containing up to, 40% of SO ),'and the mixture isheated for 810 hours to aboutl45150 C; The quinizarine-2-carboxylic acidthus formed is precipitated by pouring the meltinto water, filtering andwashing. v

EwampZe eon, c 0011. /(J O\ i -'0 002B 002B (1% 002E on 0 OH 10 parts byweight of 2-metho xy-5'-hydroxy- U benzophenone-24 -dicarboxylic acid ofthe melting point 232 O, (obtainable from2- methoxy-5-chlorobenzophenone2,4 dicar boxylic acid by heating to C. with sodium acetate, potassiumcarbonate and copper bronze) are introduced into 100 parts by Weight offuming sulfuric acid of 20% strength,

methylether of quinizarine-3-carboxylic acid thus formed is precipitatedby pouring the melt into Water, boiling up, filtering and washing. Itcrystallizes from glacial acetic acid in red-brown prisms, melting at215 Example 5 O OCH:

benzophenone-2.4-dicarboxylic acid are introduced into'a solution of 24parts by Weight of crystallized boric acid dissolved, in parts by weightof concentrated sulfuric acid .and the mixture is heated for about 5-,6hourstl and the mixture is heated for; about I 1520 minutes on the waterbath. The mon'o- -1'i:

on the water bath. The quinizarine-2-carboxylic acid is precipitated bypouring the melt into water, boiling up, filtering and washing. It meltsat 249250 C.

We claim 1. Process which comprises reacting upon a compound of theformula E Oa1kyl z ooon coon wherein m and 3 mean hydrogen or halogen,at least one 3/ being hydrogen, a me ans hydrogen or halogen with acompound of the group consisting of concentrated sulfuric acid andfuming sulfuric acid.

2. Process which comprises reacting upon a compound of the formulaO-alkyl 1! O v u I z COOH COOH wherein m and y mean hydrogen or halogen,at least one y being hydrogen, a means hydrogen or halogen with acompound of the group consisting of concentrated sulfuric acid andfuming sulfuric acid in the presence of boric 7 acid.

a compound of the formula y E OCH: 3

\coon COOH wherein 0c and 3 mean hydrogen or halogen, at least one 3/being hydrogen, 2 means hydrogen or halogen with a compound of the groupconsisting of concentrated sulfuric acid and fuming sulfuric acid of aS0 content up to at a temperature between room temperature and 200 C.

4. Process which comprises reacting upon a compound of the formula (6OCH 0 00011 OOOH wherein m and y mean hydrogen or halogen, at least oney being hydrogen, a means hydrogen or halogen with a compound of thegroup consisting of concentrated sulfuric acid and 3. Process whichcomprises reacting upon perature between room temperature and 5. Processwhich comprises reacting upon the compound of the probable formula (I?OOH! ooon with a solution of boric acid in a compound ofthe groupconsisting of concentrated sulfuric acid and fuming sulfuric acidcontaining up to 40% of S0 at atemperature of about 90-150 C.

' 6. The products of the general formula wherein 10 means hydrogen oralliyl, z hydropounds forming yellow to red needles solu- 'ble in strongsulfuric acid with a yellow to bluish-red coloration, in alkalies withared to blue coloration.

7. The products of the probable general formula OH I a I ooon a: wherein00 means hydrogen or chlorine, said compounds being yellow toyellow-brown crystals.

In testimony whereof, we aflix our signatures.

' SEBASTIAN GASSNER.

BERTHOLD BIENERT.

fuming sulfuric acid of a SO content up to 60% in the presence of boricacid at a tem-v

